St. Louis Rams wide receiver Mike Sims-Walker went all out to honor his father.

In August 2009, Mike Walker legally changed his name to Mike Sims-Walker in a tribute to his father, Mike Sims, who died a year earlier from colon cancer.

"He just passed away out of the blue," Sims-Walker said. "That was very devastating for me. He was my everything, my best friend. He is who I am today."

Sims-Walker founded the Mike Sims-Walker Foundation in 2010 to help provide scholarships for students in his hometown of Orlando, Fla. He also speaks out about the awareness of colon cancer and the importance of checkups.

Now 26, Sims-Walker dedicated his life to his father. And his career began to flourish after the name change.

The 6-foot-2, 212-pound receiver was signed by St. Louis as a free agent last month. He has quickly moved toward the top of the crowded mix at wide receiver.

Sims-Walker caught a 6-yard touchdown pass on the first drive Friday in the Rams' 14-10 win at Kansas City.

A big-play scoring threat, Sims-Walker has caught two passes for 26 yards in helping the Rams to a 3-0 preseason record going into the final exhibition game Thursday at Jacksonville.

Sims-Walker has built up a rapport with quarterback Sam Bradford. After a two-hour practice on Monday, Sims-Walker stayed on the field to catch more passes from Bradford, a common occurrence during training camp.

"The quarterback is comfortable with him and I think that's important for a wide receiver," St. Louis coach Steve Spagnuolo said. "He's really grasped the playbook."

Sims-Walker, in his fifth season, was chosen by Jacksonville in the third round of the 2007 draft. He suffered a season-ending knee injury in the final exhibition game of his rookie season and caught just 16 passes for 217 yards in 2008.

Then he put together a breakout season catching 63 passes for 869 yards, both team highs in 2009. He had 43 catches for 562 yards and seven TDs last season.

He was not offered a contact by Jacksonville and looked at several teams before choosing the Rams, who gave him a one-year deal that could reach $3.7 million including incentives.

Sims-Walker is working hard to prove he belongs in St. Louis. He is eager for the season to get started.

"We're a little over a week from the real deal," he said. "It's critical right now. We've got to buckle down."

The exhibition game against his former team also carries some importance. Sims-Walker remains upset that the Jaguars did not try to re-sign him.

He says he doesn't carry a chip on his shoulder but rather, "a crack, it's bigger."

Notes: St. Louis linebacker James Laurinaitis, the leading tackler last season, missed practice on Monday due to a pectoral muscle strain. He expects to play at Jacksonville. "It just gets sore a little bit," Laurinaitis said. "If I had to play tomorrow, I'd be suiting up and heading out there." ... St. Louis released veteran linebacker Na'il Diggs on Monday. Diggs, a 12-year veteran, started 12 games last season and made 37 tackles. He will likely be replaced by Brady Poppinga. "That was a hard move,' Spagnuolo said. ... "He's a classy individual and we wish him well."